CN111937212A - battery cell - Google Patents

Abstract

The present invention provides a solid battery cell that maintains the sealing properties of its outer packaging while effectively improving the volumetric energy density of a battery module. A battery cell 1 comprises a battery 10 and an outer packaging 2 for housing the battery. The battery 1 comprises a positive electrode, an electrolyte, and a negative electrode. The outer packaging 2 comprises a folded portion 21 formed by folding a film to house the battery 1, and joints 22a, 23a, and 24a formed by joining the ends of opposing films.

Description

battery cell

technical field

The present invention relates to a battery cell.

Background technique

In recent years, the demand for high-capacity, high-output batteries is rapidly expanding due to the spread of electrical and electronic devices of various sizes, such as automobiles, personal computers, and mobile phones. Examples of such a battery include a liquid battery cell using an organic electrolytic solution as an electrolyte between the positive electrode and the negative electrode, a solid battery cell using a flame-retardant solid solid electrolyte instead of the organic electrolyte solution electrolyte, and the like.

A solid-state battery with a solid electrolyte, compared to a battery with an organic electrolyte as the electrolyte, is more excellent in terms of improved safety and higher energy density because the electrolyte is non-flammable, and is currently attracting attention ( For example, Patent Document 1).

On the other hand, as such a battery, there is known a laminated cell type battery in which a rectangular parallelepiped-shaped cell is wrapped with a laminated film and sealed in a plate shape, and is used in an EV (electric vehicle) or HEV (hybrid vehicle). ) and other applications, a battery pack (hereinafter, sometimes referred to as a battery module or a solid battery module.) is used, and a plurality of such laminated cell type batteries are arranged and housed in a case. By wrapping with the outer package, it is possible to prevent atmospheric air from entering the battery.

For example, there is disclosed a solid battery including a laminated cell that can easily specify the leakage of gas from an outer package such as a pack case (for example, Patent Document 2). In Patent Document 2, it is described that even if gas leakage occurs in the outer package, the location where such leakage occurs can be easily specified.

[Prior Technology Literature]

(patent literature)

Patent Document 1: Japanese Patent Laid-Open No. 2017-147158

Patent Document 2: Japanese Patent Laid-Open No. 2012-169204

SUMMARY OF THE INVENTION

[Problems to be Solved by Invention]

However, when wrapping and sealing the battery with a film, two films are usually used to wrap the battery, and the four sides of the opposite films are joined and sealed.

However, from the viewpoint of the sealing performance of the outer package, the bonding portion formed by bonding the films needs to be bonded over a predetermined area or more, and the bonding portion itself is formed by arranging a plurality of battery cells and accommodating them in the case. In the case of , a so-called dead space occupying the space inside the casing is formed. The useless space may cause a decrease in the volumetric energy density of the battery module.

Furthermore, it is desirable to increase the area of this junction part as much as possible from the viewpoint of the airtightness of the outer package. When joining and sealing the sides of the laminate, it is necessary to increase the joining area of the joining portion, and further increase the above-mentioned useless space from the viewpoint of securing the sealing property as the thickness of the individual body increases.

An object of the present invention is to provide a battery cell capable of maintaining the above-mentioned sealing properties of the outer package and effectively improving the volumetric energy density of the battery module.

[Technical means to solve the problem]

The inventors of the present invention have made diligent studies to solve the above-mentioned problems, and as a result, they have found that the above-mentioned problems can be solved by providing a battery cell including an outer package formed by folding a sheet of film so as to accommodate the battery. this invention.

The present invention provides a battery cell including a battery and an outer package for accommodating the battery, the battery including a battery laminate in which a positive electrode layer, an electrolyte layer, and a negative electrode layer are laminated in at least this order, and the outer package The body includes a folded portion formed by folding one film so as to accommodate the battery laminate, and a joined portion formed by joining ends of the films facing each other to each other.

Thereby, it is possible to effectively improve the volume energy density of the battery module while maintaining the airtightness of the outer package.

The aforementioned battery is a solid-state battery,

The solid-state battery may include a solid-state battery laminate in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are layered at least in this order.

and also includes a support for accommodating the battery stack,

The film extension portion of the outer package formed on both sides of the folded portion by forming the joint portion may be bent toward the support body.

The said outer package may accommodate the said battery laminated body in one cylindrical film.

The battery may further include a collector tab connected to the battery laminate, and an end portion of the collector tab on the side opposite to the battery laminate may be exposed from the outer package.

The said junction part is formed by welding.

[Effect of invention]

According to the present invention, the volume energy density of the battery module can be effectively improved while maintaining the sealing properties of the outer package.

Description of drawings

FIG. 1 is a perspective view showing an outline of a solid-state battery cell 1 of the present embodiment.

FIG. 2 is a cross-sectional view taken along line X-X of the solid-state battery cell 1 (solid-state battery 10 ) of the present embodiment in FIG. 1 .

FIG. 3 is a perspective view showing an outline of an outer package 100 included in the solid-state battery cell of the present embodiment.

FIG. 4 is a perspective view showing an outline of an outer package 200 included in the solid-state battery cell of the present embodiment.

FIG. 5 is a perspective view showing an outline of an outer package 300 included in the solid-state battery cell of the present embodiment.

FIG. 6 is a perspective view showing an outline of an outer package 400 included in the solid-state battery cell of the present embodiment.

FIG. 7 is a perspective view showing an outline of an outer package 500 included in the solid-state battery cell of the present embodiment.

8 is a schematic view showing a film forming an outer package, that is, a film having a fold line before the outer package is formed.

FIG. 9 is a perspective view showing an outline of an example of a battery cell manufacturing method for manufacturing the battery cell 600 using the thin film 60A of FIG. 8 .

FIG. 10 is a perspective view showing an outline of another example of a battery cell manufacturing method for manufacturing the battery cell 600 using the thin film 60A of FIG. 8 .

Detailed ways

Hereinafter, specific embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present invention.

[Summary of battery cell]

The battery cell according to the embodiment of the present invention includes: a battery; and an outer package that accommodates the battery. The battery may be a liquid battery cell using an organic electrolyte as an electrolyte, a battery cell having a gel-like electrolyte, or a solid electrolyte having a flame-retardant solid electrolyte as the electrolyte instead of the organic electrolyte electrolyte. battery cell. Hereinafter, a solid battery cell including a solid electrolyte will be described as an example of the battery cell.

<Solid state battery cell>

FIG. 1 is a perspective view showing an outline of a solid-state battery cell 1 of the present embodiment. The solid-state battery cell 1 of the present embodiment includes: a solid-state battery 10 ; and an outer package formed of a single film and accommodating the solid-state battery. The structure of the outer package 2 will be described later.

The solid-state battery 10 includes a solid-state battery laminate 11 , a collector tab 13 , and a support body 12 . The solid battery laminate 11 is a laminate formed by laminating a positive electrode layer, a solid electrolyte layer, and a negative electrode layer in at least this order. In addition, in this specification, "laminating at least in this order" means laminating in the order of the listed layers, and means not only direct lamination of these layers but also indirect lamination. For example, it means that other layers and the like are allowed between the positive electrode layer and the solid electrolyte layer.

In addition, a support body is provided which accommodates the solid-state battery stack and has a substantially C-shaped cross section in the stacking direction ( FIG. 2 ). The collector tab 13 is connected to the solid battery laminate, and the end portion on the side opposite to the solid battery laminate 11 side is exposed from the outer package 2 . The support body 12 accommodates the solid battery stack 11 and thus has a function of protecting the solid battery stack 11 from external impact.

The solid battery cell 1 of the present embodiment can reduce the junction area of the junction in which the films are bonded to each other, as described below, and thus can maintain the sealing properties of the outer package and effectively improve the solid state battery module's durability. Volumetric energy density.

Furthermore, in the case of a solid battery cell, since the electrolyte solution is not contained in the battery, after being accommodated in the outer package, the inside of the outer package can be evacuated. As a result, the solid battery laminate can be more firmly fixed by the outer package, and the lamination dislocation and electrode cracks caused by vibration can be suppressed, and the durability can be improved.

Hereinafter, each member of the solid-state battery cell 1 of the present embodiment will be described.

[outer packaging body]

The outer package 2 is an outer package that accommodates the solid state battery 10 . By accommodating the solid-state battery 10 using the outer package 2 , the air can be prevented from entering the solid-state battery 10 .

In addition, the outer package 2 is characterized by including one folded portion 21 formed by folding a single film so as to accommodate the solid battery stack 11 having a rectangular shape in plan view. Moreover, the outer package 2 has the top surface 25, the bottom surface 26, and also has three joining parts 22a, 23a, 24a (refer FIG. 1) by which the edge part of the mutually opposing film was joined.

The solid-state battery cell 1 of the present embodiment can reduce the number of film-bonded solid-state battery cells that are bonded to each other as compared with a solid-state battery cell that uses two thin films to wrap the solid-state battery and joins the four sides of the films facing each other so as to be sealed by four joining portions. It can effectively improve the volume energy density of the solid-state battery module and prevent the formation of useless spaces.

Further, when two films are used to wrap the battery, and the four sides of the films facing each other are joined and sealed, the two films can be processed to form a deep-drawn shape so as not to apply stress to the battery as much as possible. An outer package is formed. However, there is a limit to the formation of such a deep-drawn shape, and if the thickness of the solid-state battery exceeds 20 mm, it is difficult to process these two thin films to form a deep-drawn shape.

If it is an outer package formed by folding a single film, since the film is not formed into a deep-drawn shape, it can also be used for solid-state batteries with a thickness of more than 20 mm. Therefore, the thickness of the battery is not particularly limited, and it can be effectively used in a multi-layered battery for the purpose of high voltage or high capacity in particular.

Furthermore, the outer packaging body 2 is formed by facing the film to form a joint portion, whereby film extending portions 211 and 212 are formed on both sides of the folded portion 21 . The film extension portion refers to the remaining portion of the film formed on both sides of the folded portion 21 when the film is bent so that one film is opposed to form a joint portion.

Furthermore, in the solid battery cell 1 of the present embodiment, the thin film extending portions 211 and 212 are bent toward the support body. Since the solid battery stack 11 is extremely weak against external shocks, when the film extending portions 211 and 212 are pressed against the solid battery stack 11 for bending, the pressing may become an external impact, thereby damaging the solid battery stack. body 11.

However, the solid-state battery cell 1 of the present embodiment further includes a support body 12 that accommodates the solid-state battery stack body and has a substantially C-shaped cross section in the stacking direction. The thin film extending portions 211 and 212 are pressed against the support body 12 and bent, thereby reducing the possibility of breakage of the solid-state battery. In addition, since the solid battery cell 1 of the present embodiment includes the support body 2 , the film extending portion can be easily fixed by being pressed and bent toward the support body 2 side. As long as it is a solid battery cell in which the thin film extending parts 211 and 212 are bent and fixed to the support body 2 side, the possibility that the thin film extending part can be effectively reduced when a plurality of solid battery cells are housed in parallel in the case can be effectively reduced. It becomes a protrusion and hinders the storage of the solid battery cell.

In addition, in order to prevent the occurrence of wrinkles or the like in the outer package 2, a notch (not shown) may be provided in a part of the film extending portion. In addition, the outer packaging body included in the solid battery cell of the present invention is not limited to the outer packaging body 2 described in FIG. 1 , as long as it has a folded portion and a joint portion. Other forms of the outer package included in the solid battery cell of the present invention are as follows.

(film forming outer package)

The film forming the outer package 2 is not particularly limited as long as it can form the outer package 2 that accommodates the solid battery laminate 11 . The film forming the outer package 2 is preferably, for example, a film capable of imparting airtightness to the outer package 2 .

The film forming the outer package 2 preferably includes a barrier layer including, for example, an inorganic thin film such as aluminum foil, or a non-polar oxide thin film such as silicon oxide or aluminum oxide. By providing the barrier layer, airtightness can be imparted to the outer package 2 .

Moreover, it is preferable that the film which forms the outer package body 2 is provided with the sealing layer which consists of flexible resin, such as polyethylene resin. The sealing layers laminated on the film may face each other and be joined by welding. Therefore, the step of applying the adhesive is not required. In addition, the film which forms the outer package body 2 may not have a sealing layer. An outer package may be formed by joining the films together using an adhesive.

In addition, the film forming the outer package 2 includes a substrate layer including polyethylene terephthalate, polyethylene naphthalate, nylon, polypropylene, etc., the above-mentioned barrier layer, and A laminate of the above-mentioned sealing layer. These layers may be laminated via a conventionally known adhesive, or may be laminated using an extrusion coating method or the like.

The preferable thickness of the film forming the outer package 2 may vary depending on the material used for the film, but is preferably 50 μm or more, and more preferably 100 μm or more. The preferable thickness of the film which forms the outer package body 2 becomes like this. Preferably it is 700 micrometers or less, More preferably, it is 200 micrometers or less.

One film forming the outer package may be a single-layer film or a multilayer laminate.

In addition, the shape of one film of the present invention may be a polygonal (rectangular) flat film, or may be a cylindrical film as described below.

[Solid State Battery]

FIG. 2 is a cross-sectional view taken along line X-X of the solid-state battery cell 1 (solid-state battery 10 ) of the present embodiment in FIG. 1 . The solid-state battery 10 is preliminarily accommodated in the outer package 2 , and the solid-state battery 10 includes a solid-state battery laminate 11 , a collector tab 13 , and a support body 12 . Each member constituting the solid state battery 10 will be described.

(solid battery stack)

The solid battery laminate 11 is a laminate in which at least a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are stacked, and more specifically, includes a positive electrode current collector layer, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode collector. A stack of electrical layers. Further, a plurality of this structure can be stacked as a unit cell to form a high-output battery.

(positive electrode layer)

The positive electrode layer is a layer containing at least a positive electrode active material. As the positive electrode active material, a material capable of releasing and storing conventionally known ions (for example, lithium ions) may be appropriately selected and used. Specific examples of the positive electrode active material include lithium cobaltate (LiCoO ₂ ), lithium nickelate (LiNiO ₂ ), LiNi _p Mn _q Cor O ₂ (p+q+ _r =1), LiNi _p Al _{q Cor} O ₂ (p+q+r=1), lithium manganate (LiMn ₂ O ₄ ), with Li ₁ +xMn ₂ -x-yMyO ₄ (x+y=2, M=selected from Al, Mg, Co, Heterogeneous element substituted Li—Mn spinel represented by at least one of Fe, Ni, and Zn), lithium metal phosphate (LiMPO ₄ , M=at least one selected from Fe, Mn, Co, and Ni), etc. .

(negative electrode layer)

The negative electrode layer is a layer containing at least a negative electrode active material. The negative electrode active material is not particularly limited as long as it is a negative electrode active material capable of storing and releasing ions (eg, lithium ions). For example, lithium transition metal oxides such as lithium titanate (Li ₄ Ti ₅ O ₁₂ ), TiO _2. Transition metal oxides such as Nb ₂ O ₃ and WO ₃ , metal sulfides, metal nitrides, graphite, carbon materials such as soft carbon and hard carbon, as well as metal lithium, metal indium and lithium alloys. In addition, the negative electrode active material may be in a powder form or a film form.

(Solid Electrolyte Layer)

The solid electrolyte layer is a layer laminated between the positive electrode layer and the negative electrode layer, and is a layer containing at least a solid electrolyte material. Through the solid electrolyte material contained in the solid electrolyte layer, ion conduction (eg, lithium ion conduction) can be performed between the positive electrode active material and the negative electrode active material.

The solid electrolyte material is not particularly limited as long as it has ion conductivity (for example, lithium ion conductivity), and examples thereof include sulfide solid electrolyte materials, oxide solid electrolyte materials, nitride solid electrolyte materials, and halides. Solid electrolyte materials and the like, among which, sulfide solid electrolyte materials are preferred. The reason for this is that the lithium ion conductivity is higher than that of the oxide solid electrolyte material.

(Positive current collector layer)

The positive electrode current collector layer is not particularly limited as long as it has a function of collecting current from the positive electrode layer. Examples include aluminum, aluminum alloys, stainless steel, nickel, iron, and titanium. Among them, aluminum, aluminum alloys, and stainless steel are preferred. . Moreover, as a shape of a positive electrode current collector, a foil shape, a plate shape, a mesh shape, etc. are mentioned, for example, Among them, a foil shape is preferable.

(Anode current collector layer)

The negative electrode current collector layer is not particularly limited as long as it has a function of collecting current from the negative electrode layer. As a material of a negative electrode current collector, nickel, copper, stainless steel, etc. are mentioned, for example. Moreover, as a shape of a negative electrode current collector, a foil shape, a plate shape, a mesh shape, etc. are mentioned, for example, Among them, a mesh shape is preferable.

[collector tab]

The collector tab 13 is connected to the solid battery laminate 11 , and its end portion on the side opposite to the solid battery laminate 11 side is exposed from the outer package 2 . Since the collector tabs 13 are provided, the collector tabs 13 only need to be exposed from the junctions 22 to 24 . In this way, the joint portions 22 to 24 maintain the sealing properties of the outer package, expose the collector tabs 13, and also function as power sockets.

The material that can be used for the collector tab 13 can be the same as that used for the collector tab of a conventional solid-state battery, and is not particularly limited.

In addition, the collector tab is not limited to being connected to one side of the solid-state battery laminate shown in FIG. 1 . For example, each of the collector tabs may be respectively connected to both sides of the solid battery laminate (eg, FIGS. 9( d ) and 10 ( d )).

[support body]

The support body 12 is a member that accommodates the solid battery stack 11 . The support body 12 accommodates the solid battery stack, and thereby has a function of protecting the solid battery stack 11 from external impact.

The shape of the support is not limited as long as it covers at least a part of the solid battery stack so as to accommodate the solid battery stack. For example, as shown in FIG. 2 , the support body may have a substantially C-shaped cross section in the direction of lamination. Furthermore, a structure in which a collector tab is connected from the end portion of the solid battery laminate which is not covered with the support may be used.

The material of the support body 12 is not particularly limited, and preferably a material having rigidity, for example, resins including polyethylene terephthalate, polyethylene naphthalate, nylon, polypropylene, etc.; natural Rubber such as rubber and silicone rubber; metals (including alloys) such as stainless steel or aluminum; and ceramics, etc. In addition, if the support body is made of rubber, it has the effect of buffering external shocks, and also has a high coefficient of friction, so it has a high electrode holding force.

The thickness of the support body 12 is not particularly limited, but is preferably 0.01 mm or more, and more preferably 0.1 mm or more. By setting the thickness of the support body 12 to be 0.01 mm or more, it is possible to reduce the possibility of damage to the solid-state battery due to external impact including pressing of the film extending portion. In addition, from the viewpoint of productivity and the like, the thickness of the support body 12 is preferably 1 mm or less.

<Manufacturing method of solid battery cell>

As a method of manufacturing a solid battery cell, for example, a method including the following steps: (1) manufacturing the solid battery 10 and a film forming the outer package 2; (2) folding the film to accommodate the solid battery laminate 11, thereby forming The folded portion 21, and the joint portions 22 to 24 for joining the ends of the films facing each other to each other; and, (3) the film extension portions to be formed on both sides of the folded portion 21 in the solid battery laminate 11 211 and 212 are bent toward the support body 12 side.

In the solid-state battery 10 , the above-described positive electrode, solid electrolyte layer, and negative electrode are stacked in this order, thereby producing a solid-state battery laminate 11 . In addition, after laminating the positive electrode, the solid electrolyte layer, and the negative electrode, it may be arbitrarily pressed and integrated.

In addition, the solid battery stack 11 may be accommodated by the support body 12 so that the cross section in the stacking direction of the solid battery stack may be substantially C-shaped. It is also possible to have a structure including a collector tab connected to the solid battery laminate.

The method of facing each other to join the films in each joining portion may be a dry lamination method using an adhesive, or may be formed by welding by heating, ultrasonic waves, or the like.

It is preferable to fix the film extension parts 211 and 212 with a tape or an adhesive after bending the film extension parts 211 and 212 toward the support body.

In addition, the solid battery cell of this embodiment is not limited to this manufacturing method. For example, a method may be employed in which a film obtained in the step of producing the film is used to preliminarily produce an outer package in a state where both sides have been welded, and the solid battery laminate may be bagged in the outer package. By welding both sides in advance, there is an advantage that the production cost can be suppressed.

<About battery cells other than solid battery cells>

The battery cell of the present invention is not limited to the solid battery cell provided with the above-described solid electrolyte, and may be a liquid battery cell using an electrolytic solution as an electrolyte, or a battery cell provided with a gel-like electrolyte.

The liquid battery cell includes, for example, a battery laminate formed by laminating a positive electrode layer, a separator, and a negative electrode layer in at least this order, and an electrolyte solution. The electrolytic solution is accommodated, for example, in an outer package. If it is a liquid battery cell using an electrolyte as the electrolyte, the interface resistance between the electrode and the electrolyte can be reduced compared to a solid battery with a solid electrolyte. In addition, liquid batteries can be manufactured at low cost because mass production has already been established.

In the case of a liquid battery cell, examples of the electrolytic solution include those in which LiPF ₆ , LiBF ₄ , LiClO ₄ and the like are dissolved in a solvent such as ethylene carbonate, propylene carbonate, dimethyl carbonate, or diethyl carbonate. Electrolyte that supports salt.

In addition, in the case of a battery cell having a gel-like electrolyte, it is preferable to use a combination of polyvinylidene fluoride/hexafluoropropylene (PVDF-HFP), (poly)acrylonitrile, (poly)acrylic acid, polyvinylidene An electrolyte in which a polymer such as methyl methacrylate is combined with an electrolyte and gelled.

In addition, for the positive electrode layer and the negative electrode layer other than the electrolyte, the same materials as the above-mentioned solid battery cells can be used.

<Other forms of outer packaging>

Another form of the outer package included in the solid battery cell of the present invention will be described. In addition, the same parts as those of the solid-state battery 1 of the above-described embodiment are appropriately omitted. The outer package 100 shown in FIG. 3 includes two folded portions 123 and 124 formed by folding a single film. Moreover, the outer package 100 is provided with the joining part 121a (refer FIG. 3) which joined the edge parts of the mutually opposing films.

Moreover, the outer package body 100 shown in FIG. 3 is characterized in that the top surface is provided with the joining part 125a which joined the edge parts of the mutually opposing films. In the case of the outer package 100 shown in FIG. 3 , since the joint portion is arranged on the top surface of the solid battery cell, the useless space formed by the joint portion can be reduced. Therefore, if it is a solid-state battery cell provided with the outer package 100 shown in FIG. 3 , the volume energy density of the solid-state battery module can be effectively increased.

The outer package 200 shown in FIG. 4 is provided with two folded parts similarly to the outer package 100 shown in FIG. 3 , but is characterized in that the two folded parts 223 and 224 are formed with gussets, so-called so-called gussets. The outer packaging body in the shape of horizontal gusset.

The outer package 200 shown in FIG. 4 is characterized in that it can accommodate thicker solid battery cells. That is, it is particularly useful for a solid battery cell in which multiple layers are stacked for the purpose of increasing the voltage or capacity of the solid battery cell.

The outer package 300 shown in FIG. 5 has one folded portion similarly to the outer package 2 shown in FIG. 1 , but is characterized in that a gusset is formed on the folded portion 321 , which is a so-called bottom corner. A brace-shaped outer package.

The outer package 400 shown in FIG. 6 has one folded portion similarly to the outer package 300 shown in FIG. 5 , but is characterized in that a substantially circular bottom surface is formed on the folded portion 421 instead of The gusset is a so-called stand-up pouch-shaped outer package.

The outer packages 300 and 400 shown in FIGS. 5 and 6 can stand the outer packages upright with the folded parts 321 and 421 as bottoms, and thus are useful from the viewpoint of the productivity of easily bagging the solid battery cells.

The outer package 500 shown in FIG. 7 is an outer package made of a single cylindrical film, and is characterized in that the solid battery laminate can be accommodated in the single cylindrical film.

In the outer package 500 shown in FIG. 7 , the joint portion can be reduced by forming one film in a cylindrical shape in advance. Thereby, the sealing property of an outer package can be improved more effectively.

In addition, the manufacturing method of the one-piece cylindrical film is not specifically limited, For example, it can manufacture by centrifugation molding, extrusion molding, etc. of resin.

8 : is a film which forms an outer package, and is a film in which the folding line before forming an outer package was formed. The fold line of the film 60A is made according to the shape and size of the battery housed in the outer package. As shown in the film 60A of FIG. 8 , the folding lines are formed in advance, whereby the operation of the subsequent step of folding the film or the step of inserting between the battery sealing films can be facilitated and the work efficiency can be improved.

The film 60A includes seal portions 61a, 61b, 62a, 62b, 63a, and 63b, and seals the seal portions 61a and 61b, the seal portions 62a and 62b, and the seal portions 63a and 63b, respectively. In addition, the relationship between the length A and the length B in FIG. 8 preferably has the relationship of A>B/2.

FIG. 9 shows the flow of manufacturing the battery cell 600 using the thin film 60A of FIG. 8 . First, as shown in FIG.9(a), the film 60A is produced by forming a fold line etc. in one film in advance. The folding line is made according to the shape and size of the battery housed in the outer package. Next, the film 60B folded in a cylindrical shape is produced so as to seal the sealing portion 61a and the sealing portion 61b ( FIG. 9( b )). Next, the battery including the battery laminate 71 and the collector tab 72 is inserted into the film 60B folded in a cylindrical shape ( FIG. 9( c )). Finally, the sealing part 61a and the sealing part 61b, and the sealing part 62a and the sealing part 62b are sealed, and the battery cell 600 is produced. According to this method of manufacturing a battery cell, since it is not necessary to press and bend the film against the battery stack 11 , the battery stack 11 will not be damaged due to pressing against the battery stack 11 . Therefore, when manufacturing by the manufacturing method of the battery cell shown in FIG. 9, it is not necessary to provide the support which accommodates this battery laminated body.

Furthermore, in the case of the method for manufacturing a battery cell shown in FIG. 9 , whether it is a solid battery cell including a solid electrolyte, a liquid battery cell using an organic electrolyte as an electrolyte, or a battery including a gel-like electrolyte Monomers are suitable for use.

FIG. 10 is a flow chart of manufacturing a battery cell 600 by a method different from that in FIG. 9 using the thin film 60A of FIG. 8 . The difference from FIG. 9 is that the battery laminate 71 (battery) is placed on the film with the fold lines formed ( FIG. 10( b )), and the sealing portion 61 a and the sealing portion 61 b are folded into a tube so that the sealing portion 61 a and the sealing portion 61 b are sealed. form ( FIG. 10( c )), instead of inserting the battery including the battery laminate 71 and the collector tab 72 into the film 60B folded into a cylindrical shape.

By placing the battery laminate 71 on the film formed with the fold lines, and sealing between the sealing portions, the battery can be accommodated without gaps compared to the method of manufacturing a battery cell shown in FIG. 9 . Thereby, the volume energy density of the battery module can be effectively increased.

The battery cell 600 manufactured by the battery cell manufacturing method shown in FIGS. 9 and 10 has a folded portion and a joint portion formed by folding a sheet of film so that the battery can be accommodated in the outer package. Therefore, it is possible to The airtightness of the outer package is maintained, and the volumetric energy density of the battery module is effectively increased. Furthermore, by arranging the bonding surface perpendicular to the direction in which the battery cells are stacked, the volume energy density of the battery module can be further improved.

In the case of a solid battery cell including a solid electrolyte, it is preferable to evacuate the inside of the outer package when sealing the sealing portion and the sealing portion. Also, atmospheric pressure is uniformly applied to the end surface of the battery cell in which the folded portion is formed, whereby the solid battery laminate can be more firmly fixed by the outer package. In addition, it is possible to suppress lamination dislocation and electrode cracks of the solid battery laminate due to vibration, and to improve durability.

As described above, the battery cell of the present invention can maintain the airtightness of the outer package and effectively improve the volume energy density of the battery module.

reference number

1 battery cell (solid battery cell)

10 battery (solid battery)

11 Battery stack (solid battery stack)

12 Support body

13, 72 collector tab

2, 100, 200, 300, 400, 500 outer packaging

21, 123, 124, 64 Folding part

22a, 23a, 24a, 121a, 125a, 221a, 225a, 323a, 324a, 423a, 424a, 521a Joints

25, 65 top surface

26, 66 Bottom

211 Film extension

212 Film extension

223, 224, 321 folded part (gusset)

421 Folded part (bottom part)

60A Film

61a, 61b, 62a, 62b, 63a, 63b Seal

71 Battery stack

60B Film folded into a tube

600 battery cells

Claims (6)

1. A battery cell comprising a battery and an outer package for accommodating the battery, The aforementioned battery includes a positive electrode, an electrolyte, and a negative electrode, The said outer package is equipped with the folded part which folded one film so that the said battery may be accommodated, and the junction part which joined the edge parts of the said film facing each other. 2 . The battery cell according to claim 1 , wherein the battery includes a battery laminate in which a positive electrode layer, an electrolyte layer, and a negative electrode layer are layered at least in this order, 2 . The outer package includes a folded portion formed by folding a single film so as to accommodate the battery laminate, and a joint portion formed by joining ends of the films facing each other to each other. 3. The battery cell according to claim 1 or 2, wherein the battery further includes a support for accommodating the battery laminate, The said joining part is formed so that the film extension part of the said outer package on both sides of the said folded part is bent toward the said support body side. 4 . The battery cell according to claim 1 , wherein the outer package accommodates the battery laminate in a single cylindrical film. 5 . 5 . The battery cell according to claim 1 , wherein the battery further includes a collector tab connected to the battery stack, 5 . The end portion of the collector sheet on the side opposite to the battery laminate side is exposed from the outer package. 6 . The battery cell according to claim 1 , wherein the joining portion is formed by welding. 7 .

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